Brooches Jewels : Tiffany and Co. Schlumberger 18k yellow gold conch shell brooch with blue enamel… 24 August 2018 3713 Brooches Jewels : Tiffany and Co. Schlumberger 18k yellow gold conch shell brooch with blue enamel accent. Signed Tiffany & Co., Schlumberger, 18k Measure 2 1/2″ x 2 1/4″ Weight 30.6 dwt